ans is D. Most items are features in the spinal cord, but the hippocampus is in the brain.
That is a chemical change or reaction.
Certain fossils, called index fossils, help geologists match rock layers. To be useful as an index fossil, a fossil must be widely distributed and represent a type of organism that existed for a brief time period. Index fossils are useful because they tell the relative ages of the rock layers in which they occur.
UHHHH I think it’s F because organisms are all different therefore can’t have the same patterns?
I believe that the food web is more stable
